This invention relates to a method for dispensing measured quantities of materials for mixing into a larger batch which is particularly but not exclusively designed for dispensing micro-nutrients in powder or particulate form into a batch of feed for animals.
It is often desired to mix into bulk materials smaller components to complete a recipe required for the finished product. Thus for example in feed products for animals such as pigs, poultry and the like, the bulk materials can comprise grain or other feed products but it is often required to add to the bulk feed micro nutrients so as to provide a required mix of the materials for feeding to the animals. Thus for example in a ton of the mixed feed, there may be up to eight or even up to sixteen or in some cases even up to fifty different micro nutrients which might be supplied in small amounts such 0.5 up to 5.0 kilograms. The micro nutrients when measured are dispensed into the mixing chamber with the bulk materials for mixing.
Up till now there has not been any effective system for computer controlled management of the micro nutrient ingredients so that these materials can be properly weighed and dispensed into the mixing without the necessity for manual intervention.
It is one object of the present invention therefore to provide an improved method and apparatus for measuring and dispensing materials. The method can be used for example in mixing food stuffs but this is only one example of suitable end uses.
According to one aspect of the invention there is provided a method for dispensing measured quantities of particulate material comprising:
providing a duct;
providing at least one hopper containing the material to be dispensed;
connecting the hopper to the duct so that material can be dispensed from the hopper to the duct;
generating an air flow through the duct to carry the material from the hopper along the duct;
controlling flow of material from the hopper to the duct through an air lock valve which prevents flow of air from the duct to the hopper;
providing a separator container in the duct such that the material in the duct carried by the air flow passes to the separator container;
in the separator container separating the material from the air flow to deposit the material into the container while the air flow is discharged from the container;
weighing the deposited material while the material is maintained in the separator container and controlling the air lock valve so as to continue to discharge the material up to a predetermined weight and to halt the discharge when the predetermined weight is reached;
and discharging the deposited material from the separator container.
Preferably the separator container is mounted on a weighing system to effect weighing thereof with the material inside.
Preferably the container is mounted on load cells.
Preferably there is a plurality of hoppers each for a different material and each is connected to the duct for discharge through an air lock valve for sending material to the separator container.
Preferably in a batch of materials, all of the materials are sent to the container before the materials are discharged.
Preferably materials from the container are discharged into a mixing container.
Preferably the mixing container includes bulk materials into which the materials from the hoppers are mixed.
Preferably the separator container includes a centrifugal separating section.
Preferably the duct injects the mixed air flow and materials tangentially into the centrifugal separator.
Preferably the centrifugal separator includes a central filter section through which the air is withdrawn.
Preferably the air is pulled by vacuum from the separator.
Preferably the separator container is mounted on legs each of which includes a load cell.
Preferably hoppers are arranged in a row along the duct and are computer controlled in response to an input of the predetermined weight of each material required and the measured weight in the container.
Preferably the materials are micro-nutrients for mixing into bulk feeds for feeding to animals.
According to a second aspect of the invention there is provided an apparatus for dispensing measured quantities of particulate material comprising a duct; at least one hopper for containing the material to be dispensed; the hopper being connected to the duct so that material can be dispensed from the hopper to the duct; means for generating an air flow through the duct to carry the material from the hopper along the duct; a separator container in the duct such that the material in the duct carried by the air flow passes to the separator container; means in the separator container for separating the material from the air flow to deposit the material into the container while the air flow is discharged from the container; and means for weighing the deposited material while the material is maintained in the separator container and controlling the air lock valve so as to continue to discharge the material up to a predetermined weight and to halt the discharge when the predetermined weight is reached.